Effects of the Improvement in Thermal Conductivity Coefficient by Nano-Wollastonite on Physical and Mechanical Properties in Medium-Density Fiberboard (MDF)

Maderas, Cienc. tecnol.

Mohammad-Panah

Morrell

2016

The effects of wollastonite fibers on the physical and mechanical properties of medium-density fiberboards composed of wood fibers with up to 10 % camel-thorn chips were studied. Approximately 30 % of the wollastonite fibers were less than 100 nm while the remainder were less than 1 μm. Wollastonite fibers significantly improved most of the physical and mechanical properties while addition of camel-thorn produced more variable effects on panel properties. Up to 10 % camel-thorn could be added to panels without negative effects. A combination of 10% camel-thorn and 5% wollastonite fibers produced panels with the best properties.

Section: Introductionmentioning

confidence: 99%

Effects of wollastonite on the properties of medium-density fiberboard (MDF) made from wood fibers and camel-thorn

Maderas, Cienc. tecnol.

Mohammad-Panah

Morrell

2016

“…Wollastonite nanofibers are reported to improve dimensional stability in solid woods (Haghighi et al 2014) and to significantly increase thermal conductivity coefficients in medium-density fiberboards (MDF) (Taghiyari et al 2014a) due to the high thermal conductivity of wollastonite . Our study was carried out to assess the effects of wollastonite on gas and liquid permeability in MDF.…”

Section: Introductionmentioning

confidence: 99%

Effects of wollastonite nanofibers on fluid flow in medium-density fiberboard

Samadi

2015

J. For. Res.

We studied the effect of wollastonite nanofibers on fluid flow in medium-density fiberboard (MDF). Nanowollastonite (NW) was applied in MDF at 10 %, based on the dry weight of wood fibers. We also tested chicken feathers as an additive to the matrix at 5 and 10 % by weight. The weight of feathers was reduced from the wood fibers to keep the density of the panels constant (0.66 g cm -3 ). Wollastonite nanofibers acted as filler in the matrix and significantly decreased gas and liquid permeability. Higher thermal conductivity of the NW-treated MDF-mats resulted in a better cure of resin, and consequently more integrity in the composite-matrix and lower permeability. The water-repellant property of wollastonite also contributed to the decrease in liquid permeability. Feathers reduced gas and liquid permeability due to the hydrophobic nature of keratin, as well as its formation as a physical barrier towards passing of fluids. Ten percent feather content proved too high and some checks and cracks occurred in the core of the panels after hot-pressing. Panels with 5 %-feather content resulted in both lower fluid flow and adequate physical integrity in the core section of the MDF-matrix.

“…Limiting UF resin consumption would have another privilege as far as the health issues are concerned: It will decrease formaldehyde emission in the living environment. Although utilization of UF resin is not restricted in some parts of the world (Taghiyari and Farajpour Bibalan 2013;Taghiyari et al 2014), its limitation to as much extent as possible would be beneficial to people. Using polyethylene in the particleboard matrix would not only improve …”

Section: Resultsmentioning

confidence: 99%

“…So, if by any means, there would be a possible way to use them in industry of any kinds, and two goals will be achieved at the same time: First, the problem of disposing a non-biodegradable material would be solved, and second, a value would be added to a waste material. In this connection, composite boards offer a nearly homogeneous structure (Eshaghi et al 2013); furthermore, raw materials may be used without restrictions as to the shape and size (Taghiyari et al , 2014, and there are many studies to find methods for limitation of formaldehyde emission and improve the properties (Stockel et al 2012;Valenzuela et al 2012). Composite boards and profiles are therefore expanding worldwide.…”

Section: Introductionmentioning

confidence: 99%

Improving physical and mechanical properties in particleboard by recycled polyethylene and canola residues

Rangavar

Int. J. Environ. Sci. Technol.

Ghofrani

et al. 2015

Improving effects of recycled polyethylene on dimensional stability, mechanical properties, and reduction in adhesive consumption of particleboard made from canola residues were studied here. Canola residues were consumed at 0, 30, and 50 % consumption levels, based on the dry weight of wood particles. Recycled low-density polyethylene was also consumed at two levels of 20 and 30 %. Urea-formaldehyde resin was used for all treatments at three levels (6, 8, and 10 %). Results showed that polyethylene had significant improving effects on all the physical and mechanical properties. Increase in canola content, however, increased modulus of rupture and modulus of elasticity due to the more slenderness ratio of canola residue, but it decreased the internal bond and physical properties because of the higher specific surface area of canola particles. Properties of the panels made from 30 % canola residues, 30 % polyethylene, and 8 % ureaformaldehyde resin were in compliance with the EN 312-2 standards. It can be concluded that the improving effects of recycled polyethylene can compensate for part of the ureaformaldehyde resin, and therefore, lower urea-formaldehyde content can be used, lowering the production costs due to high-value urea-formaldehyde resin. At the same time, the potentiality of formaldehyde emission into the atmosphere would also be decreased.